Looking into turbo's and would like to know how much power does every pound of boost add.. I would assume that a supercharger would gain a little less per # due to it taking more power to run it.... So on a stock motor how much hp per #. Is there a general rule/guess ..

 

Usually in teh area os 20-30. I have stock CR and i gained 70 from 2 psi, goin from 10-12. GL



John

 

There is no general rule for such a thing. A Honda might gain 15hp per pound, while a Ford GT gains 50hp per pound. It all depends on the motor, the turbo or supercharger itself, the cam, the heads, the headers, all of the bolt-ons, etc...

 

as ferocity says there is no rule of thumb to follow.... too many variables with two of the biggest variables being the tune and the FI unit itself.

You might be able to get a good guess you say what FI unit you plan to use and the current engine setup.

 

bamo!
https://ls1tech.com/forums/forced-induction/208864-turbo-faq.html

 

come on guys, were talking LS1 here. Stock everything. Thanx smoking-hawk, i did see the faq but missed this part
how much power will i make if im running Xpsi or increase it xpsi?
there are alot of varibles and some other thing in contribution, but if you start out with what your engine makes NA
(0psi) you double the power at 1 atmosphere (14.7psi or 1 bar) so we can come up with a rough formula of
new power = [ ( NA power / 14.7 ) * amount of boost ] + NA power

that was basically looking for

 

I gained almost 200rwhp going from 7 to 12psi...

 

You and I are almost identical . . . iron 6.0, .030 over, Incon TT, pump gas ( 91 octane ), 12 psi. Got me to 617/669 running out of fuel @ 5K. Still have to get that problem fixed!

So, I gained 42rwhp going from 10-12 . . .

- Dug

 

In a nutshell, there is no said easy answer. The lowest I have seen is 15 HP/psi. The highest I have seen is 40 HP/psi. It REALLY depends on your system.

The amount of HP that you gain for a given pound of boost varies significantly with the pressure losses associated with the system and the parasitic losses associated with the system. For a supercharger this is the compressor efficiency. On a turbo system this essentially boils down to turbo inlet pressure. Additionally, you have intercooling benefits to factor in.

FYI superchargers don't always make less HP than an equivilant turbo setup. There are plenty of turbocharger setups out there that have much higher parasitic losses then a basic supercharger setup.

 

This will answer your questions.... A list i made along time ago, but if you guys want i can update it. Anyways this will give u an idea on the gains per psi on LS1 with different kits. You will notice a trend with different kits. Some has more samples than other.

https://ls1tech.com/forums/showthrea...75#post1049675

 

You still have to indicate what FI unit you are using, because size of the unit makes a big difference in the power increase.

For instance... my old SRT, with the TD04-16G (small turbo) at 15PSI the car made a best of 231FWHP. With a 50 trim t3/4 (bigger turbo) at 15PSI guys see 300 or more FWHP. Bigger units flow more even under the same pressurization..... so that will make a difference.

If you are simply looking for a pie in the sky number... I liked to work off the assumption that each 1psi would net me 10 hp.

 

lss1power thank you for the info, see i knew someone had the info

 

Yeah 14.7 or lets just say 15 psi would exactly double your HP if it where not for the dang variables. If you have high enough octane and don't have to worry about detonation then you wouldn't have to worry about that variable. The problem with boost is it greatly increases the temp of the intake charge and when you heat the intake charge the air molecules expand so you are not really doubling the intake of air even though you have doubled the pressure. If you had 15 lbs of boost and the air inlet temp was the same as when not boosted you would probably more than double the hp and the reason for that is your engine normally runs off of atmospheric pressure which is 14.7 but you have the friction losses of one engine. When you ad 14.7 lbs of boost you have doubled the air intake which would practically double the hp but you still only have the friction of one engine. Lets just say if you had a super effecient intercooler then you could take your total hp and divide it by 14.7. You would probably make around that or slightly less per pound of boost.

 

holy crap crazy good write up! must have taken a long time to gather all that info!!!!! that being said, there are alot of other factors, so you sadly have to take that list with a grain of salt. Lets say someone in that list had uncorrected numbers, for an FI car d/a and air temp are a big factor...but man thats amazing work!

 

It took me few hours, but i was bored as hell that day lol. So it was entertaining at that moment. All the numbers i gatherd were SAE. I agree there are alot of factors, but you still can see a trend with the different kits no matter what setup they had. Some kits were producing less gains per psi than others giving almost the exact setup. Hell even two cars with the same mods wont produce the exact same numbers. Its just interesting to look at. I can update and make a third list if people wants.

 

I find this guide really helpful. Read Here

 

must be a record to reply to an almost 20 year thread